Organopolysiloxanes containing phosphonic groups, method for the production and use thereof

Abstract

The invention relates to new compounds of the formula, wherein R and R¹ are each independently hydrogen, a linear or branched C_1-40 alkyl, C_2-40 alkenyl or C_2-40 alkynyl group, an aryl or C_1-40 alkylaryl group or an optionally complex metal ion Mⁿ⁺/n wherein n is an integer from 1 to 8; the free valences of the silicate oxygen atoms are saturated by one or more of: silicon atoms of other groups of the formula, hydrogen, a linear or branched C_1-12 alkyl group or by cross-linking bridge members R³_qM¹(OR²)_mO_k/2 or Al(OR²)_3-pO_p/2 or R³Al(OR²)_2-rO_r/2; where M¹ is Si or Ti; R² is linear or branched C_1-12 alkyl group; and R³ is a linear or branched C_1-6 alkyl group; k is an integer from 1 to 4 and q and m are integers from 0 to 2; such that m+k+q=4; and p is an integer from 1 to 3; and r is an integer from 1 to 2; or other known oxo metal bridging systems; x, y and z are integers such that the radio of x:y+z, varies from 0.00001 to 100,000 with the fragments [O_3/2SiCH(CH₂PO(OR)(OR¹))CH₂CH₂SiO_3/2]_X and [O_3/2SiCH₂CH₂PO(OR)(OR¹)]_Y always present whilst the integer z varies from 0 to 200y. The compounds are useful as catalysts for a wide variety of reactions and have the advantages that they can be prepared in a one-pot reaction and have functional group losding can be tailored to be at a required level. In addition, the compounds have high chemical and thermal stability, fixed and rigid structures, are insoluble in organic solvents, high resistance to ageing, and can easily be purified and reused.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to new organopolysiloxanes containing phosphonic acid groups which can act as acid catalysts, cation exchangers and possess in their characteristics a number of advantages over organic polymer systems and inorganic supporting materials. In addition the metal salts of the organopolysiloxane phosphonic acids can be used to catalyse a wide variety of chemical transformations. Precursors of these new products, processes for their production and their uses are also described.[0002]As is known, acid catalysts are utilised in the chemical and biochemical industry to conduct a wide range of chemical transformations. A range of homogenous and heterogeneous catalysts are used some of which require high temperatures to be effective and some produce considerable amount of bi-products and waste. These unwanted products and waste have to be treated and destroyed. The drive for more environmentally friendly processes—Green Chemistry—highlights...

AI Technical Summary

Problems solved by technology

A range of homogenous and heterogeneous catalysts are used some of which require high temperatures to be effective and some produce considerable amount of bi-products and waste.

These unwanted products and waste have to be treated and destroyed.

One of the problems encountered with these systems is the loss of the active functional groups due to their often very weak attachment to the silica New organo-silica materials are needed which whilst possessing the properties described above have functional groups which are strongly attached and which bind strongly to a range of metals and catalysts.

For example industries such as the nuclear industry and the electroplating industry generate substantial quantities of water-based effluent which are heavily contaminated with undesirable metal ions.

The physical and chemical properties of these polystyrene sulfonic cation exchangers are strongly affected by the organic nature of the polymeric backbone so that a number of disadvantages affect their technical field of application.

These limitations include relatively low temperature resistance 100°–130° C., sensitivity to chemical attack which can result in complete breakdown of the polymer matrix, strong swelling capacity, non-usability in certain organic solvents and the need for swelling to make the functional groups accessible.

However the physical and chemical properties of these organophosphonic acid resins are very similar to the polystyrene sulfonic acid based systems and thus likewise their field of application is limited.

However these systems suffer from the fact that only a low level of functional groups can be bound onto these surfaces.

One of the additional problems encountered with these systems is that the functional groups can be removed on use or on standing.

Whilst these materials can act as cation exchangers it is generally recognised that sulfonic acid groups are limited in their effectiveness to complex with a range of metals and in comparison to other functional groups.

In addition the sulfonate group is also limited by the fact that it is a mono anion and thus more of these functional groups are needed to bind to metals compared to other functional groups.

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